Positively-controlled maneuvering and emergency shut-off valve



Feb. 13, 1923.

' D. COCKBURN ET AL POSITIVELY CONTROLLED MA'NEUVERING AND' EMERGENCY SHUT -0FF VALVE Fi led Sept. 12,- 51921 2 sheets-sheet J POSITIVELY QONTROLLED MANEUVERING AND EMERGENCY SHUT-OFF VALVE Filed Sept. 12, 1921 2 sheets-sheet 2 I @wgm hwd7 v r "If I operation of the emergencygear the said 'Patented Feb, 13, 1923,

1.1 ET E DAVID COCKBURN AND DONALD rrAeNrooLL,

scorLa D. 7

r owner.

or oAnD'oNa'LD, NEAR 'etaseow,

Application filed September 12,1921. Serial No. 500,146.

To all whom it may concern: I Beit known that we, DAVID CooKBURN and DONALD MAoNIooLL, subjects of the King of the United Kingdom of Great Britainand Ireland, and-residing at Clydesdale Engineering Works, Cardonald, near Glasgow Scotland, having invented a certain new and useful Improvement in Positively-Controlled Maneuvering and Emergency Shut Valves, of which the following is a specification. j

This invention relates to emergency operatingdevices for positively controlled mane'uvering and emergency shut off valves of the type which are dependent for operatlon on the fall in the pressure of liquid, for example oil in an oil system, or onthe operation of hand or other controlling gear.

According to the invention there is provided a cylinder in communicationwith the main valve chest and with an auxiliary valve chest, movable in which normally exposed to fluid pressure over a greater area on'one side than -on the other side, said'piston being 'operatively connected to the main valve operating mechanism. The auxiliary valve chest is provided with three ports, one port leading to the source of pressure fluid supply and normally in communication with the first side of the piston, a

second port adapted, when open, to permit communication between the first side of the piston and the atmosphere, and a third port adapted, when open, v tion between a chamber adj acent' to the unexposed area of the second side of the piston and the atmosphere. A valve element is provided with two valve faces, the first face adapted to control the second port and the second face adapted to control the thirdport. The arrangement is such that in the valve element moves to open the second port and to close the third port, the first side of the piston is brought into communication with the atmosphere and the strained to move in the direction corresponding to the closing movement of the main valve.

The invention is illustrated in the accompanying drawing in which-Fig. 1 is a section of the main valve chest and associated parts and Fig. 2 a

cylinder is a piston to permit communicafull area of the I second side of the piston is rendered subject to fluid pressure whereby the piston is consection of the auxiliary valve chest. Referring to the drawing,,the emergency cylinder 1 is in continuous communication with the main. valve chest 10. Movable in the cylinder 1 is a piston 2 which ,is normally exposed to steam pressure over its full area on the under side butis exposed to steam pressure over less than itsfull area on th upper side, .the exposed area being reduced by the diameter of a chamber 3 provided with avalve face 4 engaging a face 5 on thepiston 2. The piston 2 is thus normal ly held in raised position and escape of steam from the cylinder 1.is prevented. A port 1 y,

connects the main valvechest 10 with-the upper end of the cylinderl. The piston 2 is operatively connected to theoperating mechanism for the valve 26 by a rod 6, a

bellcrank lever :7, a link 8 and a main lever 1 9. Connected to the main valve chest 10 is an auxiliary valve chest 11 communicating by way of a passage 12 with the source' of steam supply and vprovidedswith three ports 13, 14, 15. The port 13 leads to the passage 12 and is normally in communication with the under side of the emergency piston 2 by way of a cylindrical guide 11. The P0111141 is-adapted, when open," to permit communi- 2 and the atmosphere by way of a pipe 16.

or othercontrol gear and provided with valve faces. 143- an'd15 The face 14 is adapted to control the port 14: communicatcation between the under side of the piston inc withthe under side of the piston and I 1:113 face 15 is adapted to control theport 15 "communicating with the chamber 3. The

arrangement is such that, when the pressure in the oil. system falls, the valve element .17

moves to open the port '14 and to close the port 15, whereby the under side of the piston 2' is brought into communication with the atmosphere, and the piston 2 is caused to move in the direction corresponding to the closing movement of the main valve 26 so that the faces land 5 separate and the full area ofthe upper side of the'piston 2 is rendered subject to steam pressure, without leakage of steam through the port- 15.

Cooperatingwiththe cylindrical guide 11 in the auxiliary valve chestis'a piston element 18 which normally permits leakage of steam through the guide towards the underside'of the piston '2 and exerts no'eif'ort to move the valve element 17 so long as the face 1 is seated, thepressures on both sides of the piston element 18 being equal. When the port 14: is open, the'steam acting on the piston element 18 urges the valve element 17 away fromthe-port 1e and thus continues the movement of said valve element after the face 1r vacates-the zone influenced by the steam passing through the port 14.

v The piston element 18 isprovided with a valve face 13 'adaptedto seat on the'port 18'so as to interrupt the supply of steam through theport 12.

The valve element 17 may be conveniently operated by'handor other control gear;

In the construction shown, the valve ele- Inent 17 isactuated by'a piston 19 reciprocablefiin a cylinder'20 the underside of Which communicates with the oil system.

The piston is connected to the element 17 through a yoke 21 and levers 22 fulcrumed at 23 and connected at 24- and 25 respectively to the yoke 21 and to the element 17.

On the stem 17 of the valve element 17 is'loosely fitted a bushwl7 which assists in balancing the valve element 17.

Onfthe opening movement of the valve element 1.7 there is an effort on top of said element, there being fluid in the space above the latter.

Normally the element 18 should sustain the fluid pressure but if it should chance to 'bind it'will of course be of no assistance in inaintzitining a balance. The bush 17 however, functions as a balancing bush, 1. e., in

conjunction with the valve element 17 forms a balanced system. Should the bush 17 bind, the stem .17 of the valve element 17 is still free to slide through the bush 17 nism therefor, a piston operatively connected to said mechanism, said piston normally exposed to fluid pressure over a greaterarea on one side than the other, a cylinder in which said piston is movable, a chamber adjacent to the unexposed portion of the second side of said piston, anaux'iliary valve chest having communication with said cylinder and provided with a port leading to the source of pressure fluid supply and normally in communication with the first side or said pi ton, a second port adapted, when 1 open, to? permit communication between the first side of said piston and'the atmosphere, and a third port adapted, when open, to per mit communication between said chamber and the atmosphere, and a valve element provided with avalve face adapted to con trol the second port and a second face adapted to control the third port, said valve movable, during the 'operation'of'said mechawhich said piston is movable, achamber adjacent to the unexposed portion of 'thesec- --ond side oi said; piston, an auxiliary v valve chest havin communication with said cylinder and provided w th aport-lead ngto the source of pressure fluid supply and nor-- mally in'communicat-ion withthje first side of said piston, 21 second port-adapted, when open, to permit communication between the first side of said piston and the atmosphere, and a third port adapted, when open, torper- -mit'coinmunicatio'n between said chamber and theatmosphere, a valve'element provided wit-h a valve face adapted to" control the second portend a second face-adapted; to

'control thethirdportfsaid valve movable,-

during the operation of said mechanism, to

open the second port and close-the third port, to bring the firstside' of said piston into communication with the atmosphere and render the full area' of the second side oi said piston subject to fluid pressure whereby said piston is constrained tomove in the direction corresponding tothe closmg movement of said main valve, a cylindrical guide iii-said chest,*and--apiston ele-- ment cooperating with said-guide and controlling communication between the f source of fluidpressure supply and the first sideof said piston, said element being independent of and'abutting against said valve element.

'3. In emergency 1 valve. gear, in combination with amain'valve and main operating mechanism therefor, a piston operatively connected to said -mechanism saidpiston normally exposed to fluid pressureover a greater area onone sidethan the other, a

cylinder in which said: piston is movable, a chamber adjacent to the unexposed portion oi. the second sidejofsaid piston, an-auiriliary valve chest having communication with said cylinder and provided with a port-leading to the source 1 offpressure fluid supply and normally in communication with the first side of said piston; a second'po'rt adapted, when open, to permit communication between the first side of said piston and the atmosphere, and a third port having an exe tension and adapted, when open, to permit communication between said chamber and the atmosphere, a valve element having a stern and provided with a valve face adapted to control the second port and a second face adapted to control the third port, said valve element movable, during the operation of said mechanism, to open the second port and close the third port, to bring the first side of said piston into communication with the atmosphere andrender the full area of the second side of said piston subject to fluid pressure whereby to move in the direction corresponding to the closing movement of said main valve, and a bush in which the stem ofsaid valve element is loosely fitted and which bush is movable in anextension of the third port.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

DAVID COGKBURN. I DONALD MACNICOLLL Witnesses:

KATE Fo'rHnRINGHAM, ISABEL, Rome.

said piston is constrained 15 

